注氮GaAs中的深能级及其对自由载流子的补偿

DEEP LEVELS AND FREE-CARRIER COMPENSATION IN NITROGEN-IMPLANTED GaAs

详细研究了注氮n型GaAs中深的和浅的杂质缺陷的电学性质。深能级瞬态谱(DLTS)技术测量表明,能量为140keV和剂量为1×10^(13)cm^(-2)的氮离子注入并经800℃退火30min的GaAs中存在四个电子陷阱,E_1(0.111),E_2(0.234),E_3(0.415),E_4(0.669)和一个空穴陷阱H(0.545),而在能量为20keV和剂量为5×10^(14)cm^(-2)的氮离子注入并经同样退火的同种GaAs中,只观测到E_4和H(0.545)两种缺陷,E_2和E_3是高能量注入损伤缺陷,E_4可能是本征缺陷和注入损伤的络合物,H(0.545)是与氮有关的深能级,它可能与掺氮n型GaAs中的自由载流子受到严重补偿有关。

This work presents a detailed study of deep and shallow level defects in nitrogen implanted n-type GaAs. Deep-level transient spectroscopy (DLTS) measurements show four electron traps and one hole trap in 140 keV nitrogen implanted GaAs after a dose of 1 × 1013 cm -2and a thermal annealing at 800℃ for 30 min: E1(0.111) ,E2(0.234) ,E3(0.415) ,E4(0.669) ,and H(0.545). Meanwhile,only E4 and H(0.545) defects are observed in 10 keV nitrogen-implanted GaAs after a dose of 5 × 1014 cm-2 and the same annealing treatment. It oncluded that E2and E3correspond to the damages due to the high-energy implantation, E4may be complex of intrinsic defect and implantation damage, H(0. 545)is a nitrogen-related deep-level and may contribute to the free-carrier compensation in the nitrogen-implanted n-type GaAs.